Water Balancing chemicals are important because they prevent damage to the pool, or poor sanitation from chemical levels that are too high or too low. Water balance for pools essentially means to bring into balance, the most important being the pool pH, Total Alkalinity and Calcium Hardness levels.
Chlorine is about 10 times more effective at sanitising your water when the pH is at 7.2 rather than at a high pH level of say 8.2.